Control assistance device, control system, and control assistance method

Abstract

A control assistance device implements assistance in order to adjust a coefficient for a plurality of filters provided to a servo control device. The control assistance device comprises: a resonance detection unit that detects a plurality of resonance points in frequency characteristics between an input/output gain and an input/output phase shift, of the servo control device, measured on the basis of an input signal and an output signal having varying frequencies; and a resonance evaluation unit that calculates the priority levels of the plurality of resonance points. The resonance evaluation unit calculates the priority level on the basis of a distance between a point (-1,0) or a point (k, 0) (where k is a value less than -1) on a real axis on a complex plane, and a resonance point on a Nyquist locus calculated from the frequency characteristics between the input/output gain and the input/output phase shift.

1 . A control assistance device that performs assistance for adjusting a coefficient for a plurality of filters provided to a servo control device that controls a motor, the control assistance device comprising:
 a resonance detection unit that detects a plurality of resonance points in frequency characteristics of an input/output gain and an input/output phase shift, of the servo control device, measured based on an input signal and an output signal having varying frequencies; and   a resonance evaluation unit that calculates priority levels of the plurality of resonance points,   wherein the resonance evaluation unit calculates the priority levels on the basis of a distance between a point (-1, 0) or a point (k, 0) (where k is a value less than -1) on a real axis on a complex plane, and a resonance point on a Nyquist locus calculated from the frequency characteristics of the input/output gain and the input/output phase shift.   
     
     
         2 . The control assistance device according to  claim 1 ,
 wherein the resonance evaluation unit calculates the priority levels on the basis of the distance and a magnitude of a resonance frequency.   
     
     
         3 . The control assistance device according to  claim 1 ,
 wherein the resonance evaluation unit allocates the filters one by one from the resonance point with a highest priority level.   
     
     
         4 . A control system comprising:
 a servo control device that controls a motor; and   the control assistance device according to  claim 1 ,   the control assistance device comprising:
 detecting the plurality of resonance points in the frequency characteristics of the input/output gain and the input/output phase shift of the servo control device; and 
 calculating the priority levels of the plurality of resonance points. 
   
     
     
         5 . The control system according to  claim 4 , comprising a machine learning device that optimizes the coefficient of the filters allocated in order from the resonance point with a highest priority level based on the priority levels of the plurality of resonance points. 
     
     
         6 . The control system according to  claim 5 , wherein, even for the resonance point with the highest priority level, the machine learning device does not apply the filter when an evaluation function is not to be improved. 
     
     
         7 . The control system according to  claim 4 , comprising:
 a frequency generation device that generates a signal having varying frequencies, and inputs the signal to the servo control device; and   a frequency characteristic measurement device that measures the frequency characteristics of the input/output gain and the input/output phase shift of the servo control device based on the signal and an output signal of the servo control device.   
     
     
         8 . The control system according to  claim 4 , wherein the servo control device comprises a current feedback loop that controls a current flowing in the motor, and a feedback loop including the current feedback loop and the filters,
 the control system comprising:
 a frequency generation device that generates a first signal having varying frequencies, and inputs the first signal to the current feedback loop; and 
 a frequency characteristic measurement unit that measures the frequency characteristics of the input/output gain and the input/output phase shift of the servo control device, based on the first signal and a second signal input to the current feedback loop in the feedback loop. 
   
     
     
         9 . A control assistance method for a control assistance device that performs assistance for adjusting a coefficient for a plurality of filters provided to a servo control device that controls a motor, the control assistance method comprising:
 detecting a plurality of resonance points in frequency characteristics of an input/output gain and an input/output phase shift, of the servo control device, measured based on an input signal and an output signal having varying frequencies; and   calculating priority levels of the plurality of resonance points on the basis of a distance between a point (-1, 0) or a point (k, 0) (where k is a value less than -1) on a real axis on a complex plane, and a resonance point on a Nyquist locus calculated from the frequency characteristics of the input/output gain and the input/output phase shift.